“My judgment after balancing those two sets of information is that it’s a pretty good deal,” Powell declared on NBC’s “Meet the Press.”

“The great concern from the opposition is that we’re leaving open a lane for Iran to create a nuclear weapon in 10 to 15 years,” he added. “The reality is that they have been on a super highway for the last 10 years to create a nuclear weapon … with no speed limit.”

Powell represents a high-profile Republican endorsement for Obama’s nuclear agreement. The deal has no support from Republicans on Capitol Hill, who will vote to block it when lawmakers return to Washington later this week.